On 07.08.2017 19:57, Peter Zijlstra wrote: > On Mon, Aug 07, 2017 at 07:27:30PM +0300, Alexey Budankov wrote: >> On 07.08.2017 18:55, Peter Zijlstra wrote: > >>> In the extreme, if you construct your program such that you'll never get >>> hit by the tick (this used to be a popular measure to hide yourself from >>> time accounting) >> >> Well, some weird thing for me. Never run longer than one tick? >> I could imaging some I/O bound code that would fast serve some short >> messages, all the other time waiting for incoming requests. >> Not sure if CPU events monitoring is helpful in this case. > > Like I said, in extreme. Typically its less weird.> > Another example is scheduling a very constrained counter/group along > with a bunch of simple events such that the group will only succeed to > schedule when its the first. In this case it will get only 1/nr_events > time with RR, as opposed to the other/simple events that will get > nr_counters/nr_events time. > > By making it runtime based, the constrained thing will more often be > head of list and acquire equal total runtime to the other events.
I see and what could be the triggering condition for runtime based scheduling of groups as an alternative to hrtimer signal? >
